1 files changed, 68 insertions, 0 deletions
diff --git a/target/linux/oxnas/patches-4.4/010-arm_introduce-dma-fiq-irq-broadcast.patch b/target/linux/oxnas/patches-4.4/010-arm_introduce-dma-fiq-irq-broadcast.patch
new file mode 100644
index 0000000000..b59c06e2ab
--- /dev/null
+++ b/target/linux/oxnas/patches-4.4/010-arm_introduce-dma-fiq-irq-broadcast.patch
@@ -0,0 +1,68 @@
+--- a/arch/arm/include/asm/glue-cache.h
++++ b/arch/arm/include/asm/glue-cache.h
+@@ -156,9 +156,15 @@ static inline void nop_dma_unmap_area(co
+ #define __cpuc_flush_user_range		__glue(_CACHE,_flush_user_cache_range)
+ #define __cpuc_coherent_kern_range	__glue(_CACHE,_coherent_kern_range)
+ #define __cpuc_coherent_user_range	__glue(_CACHE,_coherent_user_range)
++#ifndef CONFIG_DMA_CACHE_FIQ_BROADCAST
+ #define __cpuc_flush_dcache_area	__glue(_CACHE,_flush_kern_dcache_area)
+ 
+ #define dmac_flush_range		__glue(_CACHE,_dma_flush_range)
++#else
++#define __cpuc_flush_dcache_area	__glue(fiq,_flush_kern_dcache_area)
++
++#define dmac_flush_range		__glue(fiq,_dma_flush_range)
++#endif /* CONFIG_DMA_CACHE_FIQ_BROADCAST */
+ #endif
+ 
+ #endif
+--- a/arch/arm/mm/Kconfig
++++ b/arch/arm/mm/Kconfig
+@@ -866,6 +866,17 @@ config DMA_CACHE_RWFO
+ 	  in hardware, other workarounds are needed (e.g. cache
+ 	  maintenance broadcasting in software via FIQ).
+ 
++config DMA_CACHE_FIQ_BROADCAST
++	bool "Enable fiq broadcast DMA cache maintenance"
++	depends on CPU_V6K && SMP
++	select FIQ
++	help
++	  The Snoop Control Unit on ARM11MPCore does not detect the
++	  cache maintenance operations and the dma_{map,unmap}_area()
++	  functions may leave stale cache entries on other CPUs. By
++	  enabling this option, fiq broadcast in the ARMv6
++	  DMA cache maintenance functions is performed.
++
+ config OUTER_CACHE
+ 	bool
+ 
+--- a/arch/arm/mm/flush.c
++++ b/arch/arm/mm/flush.c
+@@ -329,7 +329,11 @@ void flush_dcache_page(struct page *page
+ 
+ 	mapping = page_mapping(page);
+ 
++#ifndef CONFIG_DMA_CACHE_FIQ_BROADCAST
+ 	if (!cache_ops_need_broadcast() &&
++#else
++	if (
++#endif
+ 	    mapping && !page_mapped(page))
+ 		clear_bit(PG_dcache_clean, &page->flags);
+ 	else {
+--- a/arch/arm/mm/dma.h
++++ b/arch/arm/mm/dma.h
+@@ -4,8 +4,13 @@
+ #include <asm/glue-cache.h>
+ 
+ #ifndef MULTI_CACHE
++#ifndef CONFIG_DMA_CACHE_FIQ_BROADCAST
+ #define dmac_map_area			__glue(_CACHE,_dma_map_area)
+ #define dmac_unmap_area 		__glue(_CACHE,_dma_unmap_area)
++#else
++#define dmac_map_area			__glue(fiq,_dma_map_area)
++#define dmac_unmap_area			__glue(fiq,_dma_unmap_area)
++#endif /* CONFIG_DMA_CACHE_FIQ_BROADCAST */
+ 
+ /*
+  * These are private to the dma-mapping API.  Do not use directly.